Re-landing "Refactoring cl::list_storage from "is a" to "has a" std::vector."

[oota-llvm.git] / include / llvm / Support / SMLoc.h

diff --git a/include/llvm/Support/SMLoc.h b/include/llvm/Support/SMLoc.h
index 02db32794b6d7ae0ba9b836c9d4f2728e7219921..d5b4c57a8fd6e8d547a3ab536d28dba6b82fc5f1 100644 (file)
--- a/include/llvm/Support/SMLoc.h
+++ b/include/llvm/Support/SMLoc.h
@@ -12,19 +12,20 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef SUPPORT_SMLOC_H
-#define SUPPORT_SMLOC_H
+#ifndef LLVM_SUPPORT_SMLOC_H
+#define LLVM_SUPPORT_SMLOC_H
+
+#include <cassert>
 
 namespace llvm {
 
-// SMLoc - Represents a location in source code.
+/// Represents a location in source code.
 class SMLoc {
   const char *Ptr;
 public:
-  SMLoc() : Ptr(0) {}
-  SMLoc(const SMLoc &RHS) : Ptr(RHS.Ptr) {}
+  SMLoc() : Ptr(nullptr) {}
 
-  bool isValid() const { return Ptr != 0; }
+  bool isValid() const { return Ptr != nullptr; }
 
   bool operator==(const SMLoc &RHS) const { return RHS.Ptr == Ptr; }
   bool operator!=(const SMLoc &RHS) const { return RHS.Ptr != Ptr; }
@@ -38,7 +39,25 @@ public:
   }
 };
 
-}
+/// Represents a range in source code.
+///
+/// SMRange is implemented using a half-open range, as is the convention in C++.
+/// In the string "abc", the range (1,3] represents the substring "bc", and the
+/// range (2,2] represents an empty range between the characters "b" and "c".
+class SMRange {
+public:
+  SMLoc Start, End;
+
+  SMRange() {}
+  SMRange(SMLoc St, SMLoc En) : Start(St), End(En) {
+    assert(Start.isValid() == End.isValid() &&
+           "Start and end should either both be valid or both be invalid!");
+  }
+  
+  bool isValid() const { return Start.isValid(); }
+};
+  
+} // end namespace llvm
 
 #endif